1. Field of the Invention
The present invention relates to a driver device for a reed switch, and more particularly to a driver device for a reed switch which is driven for switching operation by using two magnets.
2. Related Art
A typical reed switch driver device of this type is disclosed in Published examined Japanese Utility Model Application No. Hei. 3-28286. The switch driver device disclosed is applied to a damper of a refrigerator. The driver device includes a motor. The rotary force of the motor is transmitted through a complex gear serving also as a reduction gear. The rotary force from the complex gear is transmitted to the final gear.
This gear is integral with a plate cam. A switch lever is urged against the outer surface of the plate cam by means of a spring. A magnet is attached to the distal end of this switch lever. A reed switch is provided facing the magnet.
When the magnet approaches to the reed switch, a pair of switch pieces are brought into a contact with each other, to set up an on state of the reed switch. When the magnet is apart from the reed switch, the pair of switch pieces separate from each other by their resilient forces. An off state of the reed switch is set up.
In the reed switch driver device thus constructed, only resilient forces of the switch pieces are used for the separation of the switch pieces one from the other for turning off the reed switch. When a locking, such as frozen and soft stick, takes place, the separation of the switch pieces fails. This results in switching failure. When the switch pieces are separated from each other, the switch pieces each cantilever supported bounces, leading to chattering.